There are multiple reproductive system and medical causes of light spotting before a period, according to Mayo Clinic. Such causes include pregnancy, hyperthyroidism and using an intrauterine device.
Other causes of light spotting before a period include:
- Cervical cancer and cervical polyps
- Chlamydia, gonorrhea and cervical infections
- Endometrial cancer, hyperplasia or polyps
- Changes in hormone levels
- Ovarian cancer or cysts
- Systemic diseases, including liver and kidney disease
- Sexual intercourse and vaginal trauma
- Vaginal atrophy or vaginal cancer
- Von Willebrand disease
Women who regularly experience abnormal vaginal bleeding should speak to a doctor. This is especially the case when pregnant, perimenopausal for more than 12 months, post-menopausal or under the age of eight.